CN2727748Y - Accurate ammeter - Google Patents
Accurate ammeter Download PDFInfo
- Publication number
- CN2727748Y CN2727748Y CN 200420053309 CN200420053309U CN2727748Y CN 2727748 Y CN2727748 Y CN 2727748Y CN 200420053309 CN200420053309 CN 200420053309 CN 200420053309 U CN200420053309 U CN 200420053309U CN 2727748 Y CN2727748 Y CN 2727748Y
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- CN
- China
- Prior art keywords
- resistance
- switch
- indicator light
- reometer
- series
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- Measurement Of Resistance Or Impedance (AREA)
Abstract
The utility model relates to an accurate ammeter. The resistance value of connection in parallel of each electric current level of the ammeter is equal to the added resistance of the import essential resistance that level, and one end of every added resistance is connected with a switch return circuit in series, wherein, another executive plan is that one end of the import essential resistance is connected with a first indicator light in series; the switch return circuit is composed of a second indicator light connecting with a bidirectional switch in series; the import essential resistance value and the resistance value of the first indicator light is equal to that of the added resistance and the second indicator light. The utility model is a novel ammeter which has the beneficial effect of holding original voltaic measurement function by simple improvement of common pointer type analog current and measuring the accurate electric current and circuit essential resistance without switch-in error by convenient measurement and account.
Description
One, technical field: the utility model relates to a kind of reometer survey instrument, particularly measures the analog current table of direct current or low-frequency ac electric weight.
Two, background technology: existing various pointer-type or analog reometer.Because the internal resistance RI of the internal resistance reometer of reometer is not equal to zero, therefore with the electric current in the direct metering circuit of this class table, can exist put-into error inevitably, sometimes even can make institute's measured value lose meaning.And when measuring the circuit of internal resistance the unknown, can't judge the accuracy of institute's measured value.In actual use, though also can adopt some other method (measuring electric current as the gear shift method) to overcome the put-into error that direct measurement causes, computing formula is numerous and diverse, and is difficult for keeping in mind.
Three, summary of the invention: the purpose of this utility model is exactly the above-mentioned defective that exists at prior art, and a kind of accurate measurement reometer is provided.
Its technical scheme is: each electric current at reometer keeps off the additional resistance that resistance in parallel equals this retaining input internal resistance, and inserts a switch loop in the end series connection of each additional resistance; Wherein, another embodiment is input internal resistance one end first pilot lamp of connecting; The switch loop is composed in series by second pilot lamp and two-way switch; And the resistance sum of the input internal resistance and first pilot lamp equals the resistance sum of the additional resistance and second pilot lamp.
Effect beneficial effect of the present utility model is by after the simple modifications to common pointer analog current, can make it become the measurement function that has both kept original electric current, measurements and calculations easily be can pass through again, the accurate electric current of having eliminated put-into error and a kind of New type of current table of circuit internal resistance measured.
Four, description of drawings:
Equivalent circuit diagram when accompanying drawing 1 is the utility model measurement electric current I 1.
Equivalent circuit diagram when accompanying drawing 2 is the utility model measurement electric current I 2.
Five, embodiment:
In conjunction with the accompanying drawings, dotted portion is the internal resistance R0 and the interior electric current I 0 of reometer, to equal the additional resistance Ri ' of this grade input internal resistance Ri in the current gear access in parallel resistance of pointer reometer, and in each switch loop of additional resistance one end series connection access, the primary circuit one group of pilot lamp R1 that connects, the switch loop is to be composed in series by a push-button switch K and one group of pilot lamp R2.When need to prove the resistance of calculating input internal resistance Ri and additional resistance Ri ', the internal resistance with pilot lamp R1 and R2 counts.
When carrying out current measurement, owing to give each current gear of reometer and connect the additional resistance that equals this grade internal resistance, and before each additional resistance with push-button switch in a switch be in series, elder generation places " 1 " position with the push-button switch of reometer in the measurement, pilot lamp R1 is glittering, does not promptly press the button switch (this moment the same with former table) and establishes that to record the electric current tabular value be I
1Push-button switch is pressed again and be " 2 " position, pilot lamp R1 and R2 are glittering, can detected current value I
2If, I
2≈ (1/2) I
1, I then
1Put-into error very little, tested electric current exact value I
0≈ I
1, if I
2Depart from (1/2) I
1Big more, I then
1Put-into error also big more, can utilize formula I
0=I
1I
2/ (I
1-I
2) try to achieve its accurate current value.
Another kind of technical scheme is cancellation pilot lamp R1 and R2, transforms simpler like this, directly makes additional resistance Ri ' in parallel equal this grade input internal resistance Ri and gets final product, and other measuring processs follow embodiment 1 identical.
Its principle of work, according to Nortons theorem: arbitrary tested linear stable state singly-terminal pair in source that contains always can equivalence be current source I
oWith internal resistance R
oParallel circuit.
Claims (4)
1, a kind of accurate measurement reometer is characterized in that keeping off the additional resistance (Ri ') that resistance in parallel equals this retaining input internal resistance (Ri) at each electric current of reometer, and inserts a switch loop in the end series connection of each additional resistance (Ri ').
2, accurate measurement reometer according to claim 1 is characterized in that: described input internal resistance (Ri) end first pilot lamp (R1) of connecting.
3, accurate measurement reometer according to claim 2 is characterized in that: described switch loop is to be composed in series by second pilot lamp (R2) and two-way switch (K).
4, accurate measurement reometer according to claim 1 and 2 is characterized in that: the resistance sum of input internal resistance (Ri) and first pilot lamp (R1) equals the resistance sum of additional resistance (Ri ') and second pilot lamp (R2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200420053309 CN2727748Y (en) | 2004-08-20 | 2004-08-20 | Accurate ammeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200420053309 CN2727748Y (en) | 2004-08-20 | 2004-08-20 | Accurate ammeter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2727748Y true CN2727748Y (en) | 2005-09-21 |
Family
ID=35043761
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200420053309 Expired - Fee Related CN2727748Y (en) | 2004-08-20 | 2004-08-20 | Accurate ammeter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2727748Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108802476A (en) * | 2018-06-13 | 2018-11-13 | 贵州电网有限责任公司 | A kind of DC current transformer and its current test method |
| CN113678002A (en) * | 2019-04-26 | 2021-11-19 | 株式会社自动网络技术研究所 | Current detection device and power supply control device |
-
2004
- 2004-08-20 CN CN 200420053309 patent/CN2727748Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108802476A (en) * | 2018-06-13 | 2018-11-13 | 贵州电网有限责任公司 | A kind of DC current transformer and its current test method |
| CN113678002A (en) * | 2019-04-26 | 2021-11-19 | 株式会社自动网络技术研究所 | Current detection device and power supply control device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |